Automatic tail-gate control for dump trucks



L. D. PAYNE Nov. 18, 1941.

AUTOMATIC TAILGATE CONTROL FOR DUMP'TRUCKS 2 Sheets-Sheet 2 Filed Nov. 22, 1939 INVENTOR.

Patented Nov. 18, 1941 AUTOMATIC TAIL-GATE CONTROL FOR DUMP TRUCKS Larry Delton Payne, Fort Worth, Tex.

Application November 22, 1939, Serial No. 305,660

1 Claim.

My invention relates to some simple principles of geometry, the mechanism so arranged to compel automatic leverage to open and shut an endgate on a dump-truck. As an angle decreases between the bed and the chassis, slack is obtained in a cable which releases a telescopic lever which in turn releases the end-gate and allows it to swing open to a certain point where an acute angle is formed by the telescopic lever and its governing cable. The arc-end of the cable is so equipped with a pulley or similar rolling or sliding instrument whereas at this slack-end point, with any excess pressure on the end-gate, the pulley or arc-end of the cable will roll or slide along this telescopic lever and thus complete its arc. The telescopic lever adjusts itself to the proper length (the joint between the sleeve and rod of this must be so tapered for a smooth rolling surface for the pulley). As the given angle increases when the dump-bed goes down the slack is taken up in the cable, the pulley on the arc-end of the cable again reverses its are on the lever, pressure is applied to the endgate and it is again secured to the bed, ready for the next load. The object of this invention is to provide an automatically controlled endgate operator which will be strong, durable, reliable, practical and compact, to save time and labor in opening and closing end-gates on dumptrucks. By arrangement of parts, different ratios of leverage may be applied to the end-gate by the lever and different amounts of slack may be obtained, making this improvement adaptable to nearly every model now in use.

In my three illustrations I have replaced the lines, radii, and points with examples of cable, lever, and cable conveyors to give a practical example. Figure 1 is a side View of the moving parts, showing the end-gate in sectional view. Figure 2 is a rear View of /2 of the dump-bed and chassis connection with the endgate attached and two pulley conveyors. Figure 3 is a rear-view of the dump-bed, corner shown in Figure 2, with the end-gate detached, showing a sectional view of the dump-bed and the position of pulley conveyors.

Similar numerals refer to similar parts throughout the views.

In Figure 1, the cable is attached at one end to bolt I4, then trained over pulleys 3A, 3B and 3C and attached at its other end to a clevis B which carries a pulley 'I which engages lever III. This pulley and cable arrangement is duplicated on the other side of the body. The dumpbed I swings on the axle 2 causing the angle 25 to decrease (in this example 45 decreases to 0). As the pulley conveyor 3A approaches the fixed point on the chassis at 4 the cable 5 becomes slack and is conveyed through the pulley conveyors 3A, 3B, 3C (pulley 3A is shown in the Figure 2, being an off-set point to pulley 3B) to the telescopic sleeve lever III which is axled at I I to the bed and at II and I2 to the end-gate, causing the endgate 8 to swing free until the slack is taken up in the cable 5. At this point an acute angle is formed by the cable 5 and the telescopic lever II] when more force is applied to the end-gate 8, the pulley I will roll up and along the lever I0, provided the point where the rod enters the sleeve is so planed smoothly to leave a minimum joint between the two parts of the telescopic lever, will complete its arc and allow the endgate 8 to fully open. Then when the bed goes down, the given angle at '25, which at this point is 0", increases to 45 in this illustration, the slack in the cable 5 is taken up, distributed through the conveyors, the pulley will reverse its arc, causing the telescopic lever II] to pull the end-gate 8 securely against the dump-bed, ready for the next load, automatically.

In the illustrations:

I represents dump-bed; 6 represents pulleywork to axle from bed; 25 represents the angle By fixing the pulley 30 at various points along its vertical plane and moving the pulley I to correspond, force may be brought to bear at any point along the telescopic lever. This gives a variation of strength tension to the end-gate.

The pulley 3B must also correspond in this vertical plane. By arrangement of the pulley 3B in its horizontal plane and 3A and 3C corresponding in the same plane, different slack lengths may be acquired. The lever I0 may be of any convenient length and attached where the best service may be obtained.

I claim:

An automatically controlled end gate operator for the opening of the end gate of a dump truck as the dump bed of the truck tilts upwardly, comprising: a chassis frame, a body tiltably mounted upon the frame, an end gate pivoted to the body, a cable attached at one end to the chassis frame by means of an adjustable tension bolt and trained over an offset pulley and two guide pulleys mounted on the body, a clevis attached to the other end of the cable and carrying a pulley, and a telescopic lever attached at v its ends-t0 the body and end gate, respectively, Y said last pulley slidably engaging over the telescopic lever; the pulleys and cable being so constructed and arranged that as the body tilts to a it against the body.

I LARRY DELTON PAYNE. 

